Electrically governed carburetor



Dec. 8, 1931. F. E. ROBERT 1 ELECTRICALLY GOVERNED CARBURETOR Filed Sept. 12, 1929 Patented Dec. 8, 1931 I UNITED STATES PATENT? OFFICE FLORENCE E. ROBERT, OF CHICAGO, ILLINOIS, ASSIGNOB IO STEWART-WARNER CORPO- RATION, OF CHICAGO, ILLINOIS, A CORPORATION 01 VIRGINIA 'ELEGDRICALLY GOVERNED GARBUBETOB Application filed September 12, 1929. Serialli'o. 392,206.

The purpose of this invention is to provide animproved construction for supplyin .fuel to an internal combustion engine, sai construction comprising an electrically operated pumping device whose operation shall be controlled according to the fuel requirements of the engine by regulatingthe,energizing cur.- rent automatically by means of current-governing devices in the circuit arranged to be operated in accordance with the engine speed and load. The invention consists in the elements and features of construction shown and described as indicated in the claims.

In the drawings:

Figure 1 is a partly diagrammatic view showing the electric pump and fuel tank diagrammatically connected as to circuit wiring and fuel line with the carburetor, the latter being shown in section axial with respect to the discharge conduit to the engine.

Figure 2 is a section at the line 2-2 on Figure 1.

Referring to the drawings: There is shown at 20 a main fuel supply tank in which there is shown submerged an electrically operated pump indicated in its entirety at 21, and which may be of any usual and suitable construction not requiring specific illustration or description, and which is accordingly shown in detail only to the extent of the in- Y leading electric circuit wire, 22, shown grounded at 23, and leading to the pump structure from a circuit governing device mounted at the carburetor and hereinafter more particularly described; the submerged fuel inlet valves and passages seen at 24; the fuel discharge valve seen at 25, and the fuel discharge conduit seen at 26, leading to a connection, 27, for the fuel pipe line, 28, which is shown leading to the carburetor.

The carburetor body, 30, is shown asarranged for down-draft, that is, for discharge entrance of the air supply and delivery of fuel mixture, downwardly to the engine intake, and for discharge of the fuel downwardly into the air stream for forming the fuel mixture.

In this construction the main air supply passage is seen at 31, preferably having a flow accelerating constriction at 32 at which end, its cavity, 34, constituting the fueldischarge passage and having midway in its length, that 1s, at the axis of the main air supply passage, 31, a discharge aperture, 35. i

This brldge member, which may be hereafter referred as the fuel discharge nozzle or nozzle brldge, is thus arranged for dischar e of fuel axially with respect to the air supp y passage, 31. The carburetor body is formed w th a mpple, 36, apertured in alignment w1th the axial cavity, 34, of the bridge nozzle, 33; and the fuel supply line, 28, is coupled, as seen at 37, to the mpple, 36, for delivery of fuel to the nozzle member, 33, for discharge of the fuel downwardl through the discharge port, 35, toward the engine intake, the carburetor body being mounted at its lower end on the engine body for discharge at the engine intake indicated at 40.

At the opposite side of the carburetor body, 30, from that of the nipple, 36, there is formed on the outside of said carburetor body a chamber, 39, of which the circumscribing wall is formed by an annular flange, .42, integral with the carburetor body, 30, the outer wall of said chamber being formed by a flexible diaphragm, 43, marginally clamped onto the edge of the annular flange, 42.. As shown, this marginal clamping is effected by means of the casing, 50, of a device of the nature of a rheostat for governing the pumpenergizing circuit, as hereinafter more particularly described and explained.

The rheostat comprises a casing, 50, in which there is insulatedly mounted a resistance coil, 51, flexed in the arc of a circle about a pivot of the switch member, 52, which is pivotally mounted in the casing, 50. The energizing circuit is indicated at 60, leading from asource of current shown conventionally at 61, the circuit'leading from said source, extending insulatedly into the casing, 50, and connected to the switch member, 52, which is insulated at its pivotal mounting in the casing and provided with a spring, 55, also insulatedly attached to the casing and reacting on the switch lever for holding it with its resistance-coil-contacting terminal, 57, in

contact with said coil nearthe end. of the lat ter which extends insulatedlyout-through the casing wall for connection wi-tli thelcircuit. I v I any circumstances be caused to enter the wire, 22, leadingto the; electrically operated pump, asyhereinabove switch, 52, has a short arm,.58;" cxtcndlng-in contact with-the center'of the diaphragm,

48 and the diaphragm is' provided attlie opposite side'with a spring,f46,reacting..-upon u g g tion, underwhich circumstances some liquid- Imight flow into'the chamber, 39, and escape the diaphragm in the. direction .for enlargement ofthe variable capacity chamber, that jis, for. forcing the diaphragm outwardly. against the short arm ofthe switchdever,

thereby causing the longer-arm the lever to be swung in the arc of theres stance COll forincreasingl the'portion of saidcoilwhich is involved in thecircuit, as the diaphragnr is thus 'moved 1n chamber-enlarg ng d rec-g.

tionl a description that the diaphragm constitut ng -.the-fmovable wall of the variable capacity chamber, 39, will-be normally-held vby-the .spring, 46', =in.-the position ofimaxim'iun en- .25

largement'of the chamber, and willthereby hold the rheostat switch '52 in'the position for involving the; maximum portion'oflthe .re-

sistance: coil. in the pump-energizing circuit,

under which. conditions thep'ump will be operated to. minilnum'capacity for .deliverf ing the fuel 't0 the.-carburet0r.j AI l'd it may be' furtherunderstood that when-"the 'throt-' v tle valve .is open and the engine is thereby ioperating."forjinflow offthe air s upply,;tl 1e' .-.resul ting. reduction ofv pressu'r'e at the. tuela. nozzle discharge.port,. 35 operating-"for tak-; ing'the tuel'from the fuel line fordischarge in the airstream to form. -the" "fuel mixture, also" operates "for. producing partial vacuum;

in the .varia bl'e'-'capacity chamber, causingthe diaphragm constituting the movable wall memberbf s'aid-chamber to ,befiexe'd wardly with-respect toj'the chamber'lby ex, terior atmospheric. pressure whiehiwi-ll-iper mit the spring,'-55, to react-upon -the switch. .memb'er,' 52,-to' cause its terminal to swing' over thejarc of; the resistance-coil in 'tli'efdi- "i'ection forreduci-ngthe portionlofthe-re- 1sistance-1coi'l g-which is include .d i n thejcircu'it, and. thereby incrasingthe amount of fithe. I current1'which will be transmitted"forpener; .gizing :the pum-pfinf accordance with the-pressure freductioni at the nozzle fdischargef- 35,

gine'jf lelzrequirement; v Iii-will beseen, therefore,v that'the construc--- due fto "the'velocity of the ajirfstream flowingto .thefengine, .which. corresponds, to jthe en' jgine peedandload. and; therefore, to'fth enmentioned; u The .plyin means. be understood from the'lforegoin'g for drainage of any-liquid which may under chamber, 39, as for example," if the rheost'at energized so asto lift the liquid to the level of the passage, 34, independently of the-sucthrou'gh the drain port, Iclaim:

.L'In cOmbinatiOn with aca rb'uretor for an internal combustion engine, electrically operated means for supplying fuel thereto,

governing the 2. ncombination with a carburetor for an internal combustion. engine, electricallyandmeans operated'by-engine suctionfor 1 operation of said fuel sup- H operated means for supplying fuel thereto,

aRd means operated by engine suction for varyingcorrespondingly to the variation of [engine suction the current by which the electrically operated fuel supplying means is energized.

3'. In combination; with a carburetor for an internal combustion engine, electricallyoperated' means for supplying fuel thereto, and means operated by engine suction for varying correspondingly to the. variation in engine suction the access of electriccurrent fro'm the current source to the electricallyv operated fuelsupplying means. u *4. In combination with a carburetor for an; internal combustion engine, anelectri-' .cally operated means for supplying fuel thereto,:a rheostatin the-circuit in which .the

electrically operated means is energized, and

means exposed to actuation byengine suction inthecarburetordischarge conduit and posigtively connected with the adjustable element of the rheostat'for adjusting thesame for current-increase anddecrease corresponding- 1y to ncrease and decrease of engine suction Y n-said carburetor discharge conduit;

5'. gIn'the construction defined-in claim4,

the-rheostat adjusting means-comprising a 'jvar'iable'-c apacity chamber having its cavity in communication with the carburetor discharge conduit, and its movable wall member by" whose movement the chamber. 'is enlarged *andreduced constituting the means for -op-" crating the adj ustable' elementof the- -rheostat". '6. In' combination-with a carburetor -for :m-iinternal combustion engine having a discharge'ipa'ssagearranged for connection with "125 the engine intake,- an electrically operated fuel-pump and a fuel delivery conduit-there- ;from to: the carburetor a variable-capacity chamber in. communication with said: fuel deliv'ery conduit and with the carburetor discharge passage to the engine, saidvariable capacity chamber having a movable wall member by whose movement the capacity of the chamber is varied; an electric circuit in which the electric operating means of the pump is energized, comprising the variable resistance element of a rheostat, and operating connections from the movable wall member of the variable capacity chamber to the chamber with the carburetor assage conduit.

8. In the construction de ned inclaim 6, the fuel delivery conduit comprising a duct in a bridge extending transversely through the carburetor discharge conduit and having within said conduit a fuel delivery port open-' ing at the side of the bridge toward the engine intake, the variable capacity chamber being formed on the carburetor conduit exteriorly thereof at the opposite end of said bridge from that at which the fuel delivery conduit leads into said bridge duct, said brldge duct opening at said opposite end into the variable capacity chamber for constituting the commupxication of the fuel delivery conduit therewit 9. In the construction defined in claim 6, the variable capacit chamber being formed comprising an annu ar flange rojecting laterally from the carburetor discharge conduit with its movable wall member consisting of a flexible diaphragm mar 'na'lly clamped to said annular flange, and aving switch bein operativel associated with said movable wa 1 member or movement thereby through the range of the rheostat, and a spring reactin on the movable wall member in chamber-en arging direction, whereby the current flowing in the energizing circuit is modified corres ondingly to the suction induced by fuel in ow to the engine.

11. A construction for the purpose indicated comprising in combination with the air and fuel mixture inflow conduit of an internal combustion engine, a fuel supply duct, and electrically operated means for moving the fuel throu h said duct for discharge in the air and fued mixture conduit for mixture with the air flowing therein, and a circuit in which said electrically operated means is energized; said fuel supply duct having its discharge in the conduit positioned therein suitably for the inducing of suction through the duct by air inflow through said conduit, the carburetor construction comprising an expansible and reducible chamber having suction communication with said conduit, and a wall member movable in response to the suction for varying the capacity of the chamber, and a rheostat having its resistance coil contained in said energizing circuit and its switch member operatlvely associated with the movable wall member for actuation thereby in the chamber-capacity-varying movement of said wall member for movement of the switch to reduce the extent of the resistance coil interposed in said energizing circuit corresponding y to the suction pro uced in the chamber for operating said moving wall member.

In testimony whereof, I have hereunto set my hand at Chicago, Illinois, this 27th day of August, 1929.

FLORENT E. ROBERT.

a spring lodged interiorly of said chamber normally reacting on the dia hragm for stressing it outwardly for enlarging the chamber, the rheostat being mounted o posite the outer side of the diaphragm for aving its switch member operatively connected with said diaphragm.

10. A constructlon for the purpose indicated comprising in combination with an engine carburetor, electrically energized means for moving fuel to the carburetor; a rheostat having its resistance coil in the energizing circuit, the carburetor construction comprising a variable capacity chamber having a movable wall member by whose movement the capacity of the chamber is varied, =1 ml a duct through which said chamber communicates with the fuel mixture passage leading to the engine intake, the rheostat 

